G8 leaders gathered in Northern Ireland called on Tuesday for a series of measures to crack down on tax evasion and increase the crucial exchange of cross-border financial information.
"Tax authorities across the world should automatically share information to fight the scourge of tax evasion," the G8 said in a statement during a two-day summit.
"Countries should change rules that let companies shift their profits across borders to avoid taxes, and multinationals should report to tax authorities what tax they pay where," it said.
G8 host nation Britain had been pushing at the summit for efforts to target not only illegal tax evasion but also avoidance by multinationals such as Google, Amazon and Starbucks that costs taxpayers billions in lost revenues.
The declaration, which came after talks on financial policy on Tuesday, called for greater transparency on corporate ownership, including in the developing world.
"Companies should know who really owns them and tax collectors and law enforcers should be able to obtain this information easily," the statement said.
"Developing countries should have the information and capacity to collect the taxes owed them -- and other countries have a duty to help them," it said.
It also called for extractive companies to report payments to all governments -- in a bid to end widespread bribe-paying in resource-rich countries -- and said governments should publish income from such companies.
It also urged greater efforts to promote trade, following the announcement at the summit on Monday that talks on a US-EU free trade deal will kick off next month.